c++ struct and class difference code example

Example: class is replace by structure

1) Members of a class are private by default and members of a struct are public
by default.
For example program 1 fails in compilation and program 2 works fine.

/ Program 1 
#include <stdio.h> 
  
class Test { 
    int x; // x is private 
}; 
int main() 
{ 
  Test t; 
  t.x = 20; // compiler error because x is private 
  getchar(); 
  return 0; 
} 

// Program 2 
#include <stdio.h> 
  
struct Test { 
    int x; // x is public 
}; 
int main() 
{ 
  Test t; 
  t.x = 20; // works fine because x is public 
  getchar(); 
  return 0; 
}